blob: f5ad10546fc9fe46ec6abe182ec09ee7665af30f [file] [log] [blame]
Ashish Jangam312b00e12012-10-12 15:00:03 +05301/*
2 * System monitoring driver for DA9055 PMICs.
3 *
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
5 *
6 * Author: David Dajun Chen <dchen@diasemi.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19#include <linux/platform_device.h>
20#include <linux/watchdog.h>
21#include <linux/delay.h>
22
23#include <linux/mfd/da9055/core.h>
24#include <linux/mfd/da9055/reg.h>
25
26static bool nowayout = WATCHDOG_NOWAYOUT;
27module_param(nowayout, bool, 0);
28MODULE_PARM_DESC(nowayout,
29 "Watchdog cannot be stopped once started (default="
30 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
31
32#define DA9055_DEF_TIMEOUT 4
33#define DA9055_TWDMIN 256
34
35struct da9055_wdt_data {
36 struct watchdog_device wdt;
37 struct da9055 *da9055;
38 struct kref kref;
39};
40
41static const struct {
42 u8 reg_val;
43 int user_time; /* In seconds */
44} da9055_wdt_maps[] = {
45 { 0, 0 },
46 { 1, 2 },
47 { 2, 4 },
48 { 3, 8 },
49 { 4, 16 },
50 { 5, 32 },
51 { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
52 { 6, 65 },
53 { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
54 { 7, 131 },
55};
56
57static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev,
58 unsigned int timeout)
59{
60 struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
61 struct da9055 *da9055 = driver_data->da9055;
62 int ret, i;
63
64 for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++)
65 if (da9055_wdt_maps[i].user_time == timeout)
66 break;
67
68 if (i == ARRAY_SIZE(da9055_wdt_maps))
69 ret = -EINVAL;
70 else
71 ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
72 DA9055_TWDSCALE_MASK,
73 da9055_wdt_maps[i].reg_val <<
74 DA9055_TWDSCALE_SHIFT);
Axel Lin98e4a292012-12-22 11:07:01 +080075 if (ret < 0) {
Ashish Jangam312b00e12012-10-12 15:00:03 +053076 dev_err(da9055->dev,
77 "Failed to update timescale bit, %d\n", ret);
Axel Lin98e4a292012-12-22 11:07:01 +080078 return ret;
79 }
Ashish Jangam312b00e12012-10-12 15:00:03 +053080
81 wdt_dev->timeout = timeout;
82
Axel Lin98e4a292012-12-22 11:07:01 +080083 return 0;
Ashish Jangam312b00e12012-10-12 15:00:03 +053084}
85
86static int da9055_wdt_ping(struct watchdog_device *wdt_dev)
87{
88 struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
89 struct da9055 *da9055 = driver_data->da9055;
Ashish Jangam312b00e12012-10-12 15:00:03 +053090
91 /*
92 * We have a minimum time for watchdog window called TWDMIN. A write
93 * to the watchdog before this elapsed time will cause an error.
94 */
95 mdelay(DA9055_TWDMIN);
96
97 /* Reset the watchdog timer */
Axel Lin98e4a292012-12-22 11:07:01 +080098 return da9055_reg_update(da9055, DA9055_REG_CONTROL_E,
99 DA9055_WATCHDOG_MASK, 1);
Ashish Jangam312b00e12012-10-12 15:00:03 +0530100}
101
102static void da9055_wdt_release_resources(struct kref *r)
103{
Ashish Jangam312b00e12012-10-12 15:00:03 +0530104}
105
106static void da9055_wdt_ref(struct watchdog_device *wdt_dev)
107{
108 struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
109
110 kref_get(&driver_data->kref);
111}
112
113static void da9055_wdt_unref(struct watchdog_device *wdt_dev)
114{
115 struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
116
117 kref_put(&driver_data->kref, da9055_wdt_release_resources);
118}
119
120static int da9055_wdt_start(struct watchdog_device *wdt_dev)
121{
122 return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
123}
124
125static int da9055_wdt_stop(struct watchdog_device *wdt_dev)
126{
127 return da9055_wdt_set_timeout(wdt_dev, 0);
128}
129
130static struct watchdog_info da9055_wdt_info = {
131 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
132 .identity = "DA9055 Watchdog",
133};
134
135static const struct watchdog_ops da9055_wdt_ops = {
136 .owner = THIS_MODULE,
137 .start = da9055_wdt_start,
138 .stop = da9055_wdt_stop,
139 .ping = da9055_wdt_ping,
140 .set_timeout = da9055_wdt_set_timeout,
141 .ref = da9055_wdt_ref,
142 .unref = da9055_wdt_unref,
143};
144
145static int da9055_wdt_probe(struct platform_device *pdev)
146{
147 struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
148 struct da9055_wdt_data *driver_data;
149 struct watchdog_device *da9055_wdt;
150 int ret;
151
152 driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
153 GFP_KERNEL);
154 if (!driver_data) {
155 dev_err(da9055->dev, "Failed to allocate watchdog device\n");
156 return -ENOMEM;
157 }
158
159 driver_data->da9055 = da9055;
160
161 da9055_wdt = &driver_data->wdt;
162
163 da9055_wdt->timeout = DA9055_DEF_TIMEOUT;
164 da9055_wdt->info = &da9055_wdt_info;
165 da9055_wdt->ops = &da9055_wdt_ops;
166 watchdog_set_nowayout(da9055_wdt, nowayout);
167 watchdog_set_drvdata(da9055_wdt, driver_data);
168
169 kref_init(&driver_data->kref);
170
171 ret = da9055_wdt_stop(da9055_wdt);
172 if (ret < 0) {
173 dev_err(&pdev->dev, "Failed to stop watchdog, %d\n", ret);
174 goto err;
175 }
176
177 dev_set_drvdata(&pdev->dev, driver_data);
178
179 ret = watchdog_register_device(&driver_data->wdt);
180 if (ret != 0)
181 dev_err(da9055->dev, "watchdog_register_device() failed: %d\n",
182 ret);
183
184err:
185 return ret;
186}
187
188static int da9055_wdt_remove(struct platform_device *pdev)
189{
190 struct da9055_wdt_data *driver_data = dev_get_drvdata(&pdev->dev);
191
192 watchdog_unregister_device(&driver_data->wdt);
193 kref_put(&driver_data->kref, da9055_wdt_release_resources);
194
195 return 0;
196}
197
198static struct platform_driver da9055_wdt_driver = {
199 .probe = da9055_wdt_probe,
200 .remove = da9055_wdt_remove,
201 .driver = {
202 .name = "da9055-watchdog",
203 },
204};
205
206module_platform_driver(da9055_wdt_driver);
207
208MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
209MODULE_DESCRIPTION("DA9055 watchdog");
210MODULE_LICENSE("GPL");
211MODULE_ALIAS("platform:da9055-watchdog");